Early Season Winter Storm Hits the Northern U.S. Rockies (credit: NPR)

DISCUSSION:  Areas farther north generally see their first measureable snowfall earlier than other places.  For example, Montana typically sees it first snowfall in October to November.  However, this year parts of Montana received their first snowfall earlier than normal this past weekend in late September.  In addition, given Montana’s distance from water and its generally colder temperatures (colder air has a lower capacity to “hold” moisture), individual storms usually don’t produce that much snow in comparison to places near the Great Lakes, for example.  However, from 27-29 September, Browning, MT received 48 inches of snow.  The 19.3 inches that fell in Great Falls, MT is the second highest 2-day snow total there at any time of year, not just in September, further indicating that large amounts of snow over short periods usually don’t occur in Montana.  The picture above is from a webcam in Glacier National Park after the recent snowstorm.  Given the topography and latitude of Montana, they are familiar with dealing with snow and winter storms.  However, the unusually large amount of snow and early timing of that snow could exasperate the impacts of this particular winter storm (e.g., road closures, power outages, etc.).
 
The storm was followed by unusually cold temperatures for late September/early October with lows dropping as low 7°F and 9°F on 1 and 2 October, respectively, at Browning, for example.  It is important to keep in mind that transient (occurring over a short time period) regional cooling or warming is completely different than global cooling or warming.  Global climate change is observed over large space and time scales.  Superimposed on this global change are long-term trends in regional warming or cooling.  On top of these regional longer-term trends are high-frequency variation.  The recent cold spell in the northern U.S. is an example of such high-frequency, regional variation and cannot be used to explain anything related to global climate.

To learn more about other winter weather events from around the world, be sure to click here!
 
 © 2019 Meteorologist Dr. Ken Leppert II